近年来,高光谱遥感技术日渐成熟,人工智能和机器学习技术逐渐应用于农作物生化参量反演领域,传统的人工测量农作物长势、叶片含水率和叶绿素含量等逐渐由自动化、智能化机器所替代,该技术在农作物叶片含水率反演方面发挥了重要作用,但...近年来,高光谱遥感技术日渐成熟,人工智能和机器学习技术逐渐应用于农作物生化参量反演领域,传统的人工测量农作物长势、叶片含水率和叶绿素含量等逐渐由自动化、智能化机器所替代,该技术在农作物叶片含水率反演方面发挥了重要作用,但仍有一定局限性。目前,限制高光谱技术主要应用于农作物生化参量反演中高光谱波段数较多、冗余度高的问题。笔者参考国内外学者提出各种筛选敏感波段的方法,以灌浆期小麦叶片高光谱数据和叶片含水率(Leaf Water Content,LWC)为对象,就目前较为热门和有效的差值植被指数法、归一化植被指数法、比值植被指数法、竞争性自适应重加权采样算法(CARS)、连续投影法(SPA)和随机蛙跳算法(Random Frog,RF)等方法进行对比分析。研究结果表明:可从等势图和算法运行过程得出,波段筛选方法获取的波段组合,与小麦叶片含水率有高相关性和较低的均方根误差,均能在一定程度上优化高光谱遥感技术在反演农作物生化参量上的应用。展开更多
A multispectral imaging system consisting of liquid crystal tunable filter(LCTF)and charge coupled device(CCD)camera was used to collect the images of fingernail samples at intervals of 10 nm during the spectral range...A multispectral imaging system consisting of liquid crystal tunable filter(LCTF)and charge coupled device(CCD)camera was used to collect the images of fingernail samples at intervals of 10 nm during the spectral range of 450-1 000 nm,and a multispectral image of human fingernails containing 56 bands was obtained.The accurate reflectivity information of fingernails was obtained through referring whiteboard comparative measurement method.Principal component analysis(PCA)and band index method were used to reduce the dimension of the sample images respectively and two feature spaces were obtained.Spectral angle mapping(SAM)was used to classify human fingernails in these two feature spaces.The classification accuracy were above 92.5%and 82.9%respectively.Therefore,the feature space obtained by the PCA can be used as the characteristic spectrum of human fingernails,which provides a reliable basis for the analysis of multispectral spectrum of fingernails and human health assessment in the future.展开更多
文摘近年来,高光谱遥感技术日渐成熟,人工智能和机器学习技术逐渐应用于农作物生化参量反演领域,传统的人工测量农作物长势、叶片含水率和叶绿素含量等逐渐由自动化、智能化机器所替代,该技术在农作物叶片含水率反演方面发挥了重要作用,但仍有一定局限性。目前,限制高光谱技术主要应用于农作物生化参量反演中高光谱波段数较多、冗余度高的问题。笔者参考国内外学者提出各种筛选敏感波段的方法,以灌浆期小麦叶片高光谱数据和叶片含水率(Leaf Water Content,LWC)为对象,就目前较为热门和有效的差值植被指数法、归一化植被指数法、比值植被指数法、竞争性自适应重加权采样算法(CARS)、连续投影法(SPA)和随机蛙跳算法(Random Frog,RF)等方法进行对比分析。研究结果表明:可从等势图和算法运行过程得出,波段筛选方法获取的波段组合,与小麦叶片含水率有高相关性和较低的均方根误差,均能在一定程度上优化高光谱遥感技术在反演农作物生化参量上的应用。
基金Nationnal Natural Science Foundation of China(No.61605176)
文摘A multispectral imaging system consisting of liquid crystal tunable filter(LCTF)and charge coupled device(CCD)camera was used to collect the images of fingernail samples at intervals of 10 nm during the spectral range of 450-1 000 nm,and a multispectral image of human fingernails containing 56 bands was obtained.The accurate reflectivity information of fingernails was obtained through referring whiteboard comparative measurement method.Principal component analysis(PCA)and band index method were used to reduce the dimension of the sample images respectively and two feature spaces were obtained.Spectral angle mapping(SAM)was used to classify human fingernails in these two feature spaces.The classification accuracy were above 92.5%and 82.9%respectively.Therefore,the feature space obtained by the PCA can be used as the characteristic spectrum of human fingernails,which provides a reliable basis for the analysis of multispectral spectrum of fingernails and human health assessment in the future.
